Chemical mechanical polishing slurry compositions and method using the same for copper and through-silicon via applications

ABSTRACT

Provided are novel chemical mechanical polishing (CMP) slurry compositions for polishing copper substrates and method of using the CMP compositions. The CMP slurry compositions deliver superior planarization with high and tunable removal rates and low defects when polishing bulk copper layers of the nanostructures of IC chips. The CMP slurry compositions also offer the high selectivity for polishing copper relative to the other materials (such as Ti, TiN, Ta, TaN, and Si), suitable for through-silicon via (TSV) CMP process which demands high copper film removal rates.

CROSS REFERENCE TO RELATED APPLICATIONS

The present patent application is a divisional application of U.S.patent application Ser. No. 13/929,346 which was filed on Jun. 27, 2013(now U.S. Pat. No. 8,974,692 issued on Mar. 10, 2015).

BACKGROUND OF THE INVENTION

This invention is in the field of copper and through-silicon via (TSV)chemical mechanical polishing (CMP). More specifically, it is related tothe CMP slurry compositions and method of using the slurry compositions.

The use of chemical mechanical planarization (CMP) in semiconductormanufacturing is well known to those of skill in the art. For example,CMP processing can be used to remove excess metal, such as copper, usedto form interconnects, vias and lines. Work has been done in the fieldof the invention.

U.S. Pat. No. 6,436,811 discloses a process for forming a metalinterconnect comprising the steps of forming a concave in an insulatingfilm formed on a substrate, forming a copper containing metal film overthe whole surface such that the concave is filled with the metal andthen polishing the copper-containing metal film by chemical mechanicalpolishing, characterized in that the polishing step is conducted using achemical mechanical polishing slurry comprising a polishing material, anoxidizing agent and an adhesion inhibitor preventing adhesion of apolishing product to a polishing pad, while contacting the polishing padto a polished surface with a pressure of at least 27 kPa. This inventionallows us to prevent adhesion of a polishing product to a polishing padand to form a uniform interconnect layer with an improved throughput,even when polishing a large amount of copper-containing metal during apolishing step.

U.S. Pat. No. 5,770,095 provides a polishing method including the stepsof forming a film made of material containing a metal as a maincomponent over a substrate having depressed portions on a surfacethereof so as to fill the depressed portions with the film, andpolishing the film by a chemical mechanical polishing method using apolishing agent containing a chemical agent responsible for forming aprotection film on a surface of the film by reacting with the materialcontaining a metal as a main component, thereby forming a conductivefilm in the depressed portions. U.S. Pat. No. 5,770,095 also provides apolishing agent, which is used in forming a film made of materialcontaining a metal as a main component in depressed portions of asubstrate having depressed portions on a surface thereof by using achemical mechanical polishing method, including a chemical agentresponsible for forming a protection film on the surface of a substrateto be polished by reacting with the material containing a metal as amain component.

U.S. Pat. No. 6,585,568 provides a chemical mechanical polishing slurryfor polishing a copper-based metal film formed on an insulating filmcomprising a concave on a substrate, comprising a polishing material, anoxidizing agent and water as well as a benzotriazole compound and atriazole compound. The polishing slurry may be used in CMP to form areliable damascene electric connection with excellent electricproperties at a higher polishing rate, i.e., a higher throughput whilepreventing dishing.

U.S. Pat. No. 6,679,929 teaches a polishing composition comprising thefollowing components (a) to (g):

(a) at least one abrasive selected from the group consisting of silicondioxide, aluminum oxide, cerium oxide, zirconium oxide and titaniumoxide; (b) an aliphatic carboxylic acid; (c) at least one basic compoundselected from the group consisting of an ammonium salt, an alkali metalsalt, an alkaline earth metal salt, an organic amine compound and aquaternary ammonium salt; (d) at least one polishing acceleratingcompound selected from the group consisting of citric acid, oxalic acid,tartaric acid, glycine, a-alanine and histidine; (e) at least oneanticorrosive selected from the group consisting of benzotriazole,benzimidazole, triazole, imidazole and tolyltriazole; (f) hydrogenperoxide, and (g) water.

U.S. Pat. No. 6,440,186 teaches a polishing composition comprising: (a)an abrasives; (b) a compound to form a chelate with copper ions; (c) acompound to provide a protective layer-forming function to a copperlayer; (d) hydrogen peroxide; and (e) water, wherein the abrasive ofcomponent (a) has a primary particle size within a range of from 50 to120 nm.

U.S. Pat. No. 6,838,016 discloses a polishing composition comprising thefollowing components (a) to (g): (a) an abrasive which is at least onemember selected from the group consisting of silicon dioxide, aluminumoxide, cerium oxide, zirconium oxide and titanium oxide, (b) apolyalkyleneimine, (c) at least one member selected from the groupconsisting of guinaldic acid and its derivatives, (d) at least onemember selected from the group consisting of glycine, α-alanine,histidine and their derivatives, (e) at least one member selected fromthe group consisting of benzotriazole and its derivatives, (f) hydrogenperoxide, and (g) water.

US patent application No. 2007/0167017 A1 provides a metal-polishingliquid that comprises an oxidizing agent, an oxidized-metal etchant, aprotective film-forming agent, a dissolution promoter for the protectivefilm-forming agent, and water. The application also teaches a method forproducing it; and a polishing method of using it. Also provided arematerials for the metal-polishing liquid, which include anoxidized-metal etchant, a protective film-forming agent, and adissolution promoter for the protective film-forming agent.

US 2009/0156006 discloses a chemical-mechanical polishing (CMP)composition suitable for polishing semi-conductor materials. Thecomposition comprises an abrasive, an organic amino compound, an acidicmetal complexing agent and an aqueous carrier. A CMP method forpolishing a surface of a semiconductor material utilizing thecomposition is also disclosed.

US2010/0081279 teaches an effective method for forming through-basewafer vias in the fabrication of stacked devices is described. The basewafer can be a silicon wafer in which case the method relates to TSV(through-silicon via) technology. The method affords high removal ratesof both silicon and metal (e.g., copper) under appropriate conditionsand is tunable with respect to base wafer material to metal selectivity.

As industry standards trend toward smaller device features, there is acontinuous developing for copper and TSV CMP slurries.

Thus, there is still a significant need for CMP slurries that deliversuperior planarization with high and tunable removal rates and lowdefects when polishing bulk copper layers of the nanostructures of ICchips.

The copper and TSV CMP slurry composition described herein satisfies theneed for providing high, tunable, effective polishing at desired andhigh polishing rates for polishing copper films with low defects andhigh planarization efficiency.

BRIEF SUMMARY OF THE INVENTION

In one aspect, the invention provides a copper and TSV chemicalmechanical polishing (CMP) slurry composition comprises:

a) an abrasive;

b) a chelating agent;

c) a corrosion inhibitor;

d) choline salt as copper removal rate booster and total defect reducer;

e) an organic amine;

f) an oxidizer;

g) biocide;

h) remaining is substantially liquid carrier;

wherein pH of the polishing slurry composition is between 5.0 to 8.0.

In another aspect, the invention provides a method of chemicalmechanical polishing a removal material of copper or copper-containingmaterial from a surface of a semiconductor substrate comprising stepsof:

-   -   a) providing a polishing pad;    -   b) providing a chemical mechanical polishing slurry composition        comprising        -   1) an abrasive;        -   2) a chelating agent;        -   3) a corrosion inhibitor;        -   4) choline salt as copper removal rate booster and total            defect reducer;        -   5) an organic amine;        -   6) an oxidizer;        -   7) biocide;        -   8) remaining is substantially liquid carrier;    -   wherein pH of the polishing slurry composition is between 5.0 to        8.0;    -   c) contacting the surface of the semiconductor substrate with        the polishing pad and the chemical mechanical polishing slurry        composition; and    -   d) polishing the surface of the semiconductor substrate;    -   wherein at least a portion of the surface that containing the        removal material is in contact with both the polishing pad and        the chemical mechanical polishing slurry composition.

In yet another aspect, the invention provides a method of a selectivechemical mechanical polishing comprising steps of:

-   -   a) providing a semiconductor substrate having a surface        containing copper metal films;    -   b) providing a polishing pad;    -   c) providing a chemical mechanical polishing slurry composition        comprising        -   1) an abrasive;        -   2) a chelating agent;        -   3) a corrosion inhibitor;        -   4) choline salt as copper removal rate booster and total            defect reducer;        -   5) an organic amine;        -   6) an oxidizer;        -   7) biocide;        -   8) remaining is substantially liquid carrier;        -   wherein pH of the polishing slurry composition is between            5.0 to 8.0;    -   d) contacting the surface of the semiconductor substrate with        the polishing pad and the chemical mechanical polishing slurry        composition; and    -   e) polishing the surface of the semiconductor substrate to        selectively remove the first material;        -   wherein at least a portion of the surface containing the            first material is in contact with both the polishing pad and            the chemical mechanical polishing slurry composition.

The CMP slurry compositions can further comprise a pH buffering agent;surfactant; and a biocide.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows Cu removal rates using CMP slurry compositions with orwithout choline bicarbonate added as the chemical additive.

FIG. 2 shows total defect counts using CMP slurry compositions with orwithout choline bicarbonate added as the chemical additive.

FIG. 3 shows Cu removal rates using CMP slurry compositions with cholinebicarbonate added as the chemical additive at different concentrations.

DETAILED DESCRIPTION OF THE INVENTION

The copper and TSV CMP slurry compositions and methods described hereinsatisfies the need for tunable, high removal rates, low defects, andgood planarization efficiency when used to polish copper films.

The CMP slurry composition disclosed herein comprises colloidal silicaparticles, high purity and nano-sized abrasives; chemical additivescomprising choline salts used as copper film removal rate boosting anddefect reducing agent; suitable chelating agents and surface wettingagents; corrosion inhibitors to protect copper film surface from furthercorrosion; organic amine compounds as copper removal rates boosters;oxidizing agents, and liquid carriers, such as water.

The CMP polishing slurry composition can further comprise pH adjustingagents, surfactants, and biocide.

The pH of the slurry composition is from about 5.0 to about 8;preferably from about 5.5 to 7.5; more preferably 6.5 to 7.

Abrasive particles used for the CMP polishing slurry compositionsinclude, but are not limited to, colloidal silica particles doped byother metal oxide within lattice of the colloidal silica, such asalumina doped silica particles, colloidal aluminum oxide, which includealpha-, beta-, and gamma-, and other types of aluminum oxides, colloidaland photoactive titanium dioxide, cerium oxide, colloidal cerium oxide,nano-sized diamond particles, nano-sized silicon nitride particles,mono-modal, bi-modal, multi-modal colloidal abrasive particles,zirconium oxide, organic polymer-based soft abrasives, surface-coated ormodified abrasives, and mixtures thereof. The colloidal silica particlescan have narrow or broad particle size distributions, with various sizesand different shapes. The shapes of the abrasives include sphericalshape, cocoon shape, aggregate shape and other shapes.

The CMP polishing slurry compositions contain from 0.0 wt % to 25 wt %abrasives; preferably from 0.001 wt % to 1 wt %, and more preferablyfrom 0.0025 wt % to 0.1 wt %.

The suitable chemical additives comprising choline salts in the CMPpolishing slurry compositions have a general molecular structure shownbelow:

Where, anion Y⁻ can be bicarbonate, hydroxide, p-toluenesulfonate,bitartrate, and other suitable anionic counter ions.

The suitable chemical additives comprising choline salts in the CMPpolishing slurry compositions include choline bicarbonate, and all othersalts formed between choline and other anionic counter ions.

The CMP polishing slurry compositions contain from 0.0001 wt % to 0.50wt % choline salts; preferably from 0.0010 wt % to 0.10 wt % and morepreferably from 0.0025 wt % to 0.050 wt %

The selected and suitable chelating agents include glycine, other aminoacids, and amino acid derivatives.

The CMP polishing slurry compositions contain from is from 0.01 wt % to22 wt % chelating agent; preferably from 0.025 wt % to 20 wt %. The morepreferred concentration range of the chelating agent is from 0.05 wt %to 16 wt %.

The selected and suitable corrosion inhibitors used for the CMPpolishing slurry compositions include, but are not limited to, triazoleand its derivatives, benzene triazole and its derivatives. The triazolederivatives include, but not limited to, amino-substituted triazolecompounds, bi-amino-substituted triazole compounds.

The concentration range of the corrosion inhibitor is from 0.001 wt % to0.15 wt %. The preferred concentration range of the corrosion inhibitoris from 0.0025 wt % to 0.1 wt %. The more preferred concentration rangeof the corrosion inhibitor is from 0.005 wt % to 0.05 wt %.

Organic amine compounds used to boost copper film removal rates includeethylene diamine, propylene diamine, other organic diamine compounds,and organic amine compounds containing multi amino groups in the samemolecular framework.

The CMP polishing slurry compositions contain from 0.0001 wt % to 0.20wt % amine compounds; preferably from 0.0010 wt % to 0.10 wt % and morepreferably from 0.0025 wt % to 0.050 wt %.

Oxidizers used for the CMP polishing slurry compositions include, butare not limited to, periodic acid, hydrogen peroxide, potassium iodate,potassium permanganate, ammonium persulfate, ammonium molybdate, ferricnitrate, nitric acid, potassium nitrate, and mixtures thereof.

The preferred oxidizer is hydrogen peroxide.

The CMP polishing slurry compositions contain from 0.01 wt % to 10 wt %oxidizers; preferably from 0.25 wt % to 4 wt %, and more preferably from0.5 wt % to 2 wt %.

pH adjusting agents used for the CMP polishing slurry compositionsinclude, but are not limited to, nitric acid, hydrochloric acid,sulfuric acid, phosphoric acid, other inorganic or organic acids, andmixtures thereof.

The preferred pH adjusting agent is nitric acid.

The CMP polishing slurry compositions contain from 0.01 wt % to 0.5 wt %pH adjusting agent; preferably from 0.05 wt % to 0.15 wt %.

In certain embodiments, a surfactant is added to the polishingcomposition as surface wetting agent. The suitable surfactant compoundsthat may be added to the polishing composition as surface wetting agentinclude but are not limited to, for example, any of the numerousnonionic, anionic, cationic or amphoteric surfactants known to thoseskilled in the art.

The following four types of surfactants can be used as disclosed hereincopper

CMP slurry as surface wetting agents:

a). non-ionic surface wetting agents, these agents typically are oxygen-or nitrogen-containing compounds with various hydrophobic andhydrophilic moieties in the same molecules, the molecular weight rangesfrom several hundreds to over 1 million. The viscosities of thesematerials also possess a very broad distribution.b). anionic surface wetting agents, these compounds possess the negativenet charge on major part of molecular frame, these compound include, butnot limited to the following salts with suitable hydrophobic tails, suchas alkyl carboxylate, alkyl sulfate, alkyl phosphate, alkylbicarboxylate, alkyl bisulfate, alkyl biphosphate, such as alkoxycarboxylate, alkoxy sulfate, alkoxy phosphate, alkoxy bicarboxylate,alkoxy bisulfate, alkoxy biphosphate, such as substituted arylcarboxylate, substituted aryl sulfate, substituted aryl phosphate,substituted aryl bicarboxylate, substituted aryl bisulfate, substitutedaryl biphosphate etc. The counter ions for this type of surface wetting;agents include, but not limited to the following ions, such aspotassium, ammonium and other positive ions. The molecular weights ofthese anionic surface wetting agents range from several hundred toseveral hundred-thousands.c). cationic surface wetting agents, these compounds possess thepositive net charge on major part of molecular frame, these compoundinclude, but not limited to, the following salts with suitablehydrophobic tails, such as carboxylate, sulfate, phosphate,bicarboxylate, bisulfate, biphosphate, etc. The counter ions for thistype of surface wetting agents include, but not limited to, thefollowing ions, such as potassium, ammonium and other positive ions. Themolecular weights of these anionic surface wetting agents range fromseveral hundred to several hundred-thousands.d). ampholytic surface wetting agents, these compounds possess both ofpositive and negative charges on the main molecular chains and withtheir relative counter ions. The examples of such bipolar surfacewetting agents include, but not limited to, the salts ofamino-carboxylic acids, amino-phosphoric acid, and amino-sulfonic acid.

The CMP polishing slurry compositions contain from 0.00 wt % to 1.0 wt %surfactants; preferably from 0.0001 wt % to 0.25 wt % and morepreferably from 0.0005 wt % to 0.10 wt %.

In some embodiments, the surfactant(s) are nonionic, anionic, ormixtures thereof and are present in a concentration ranging about 1 ppmto about 1,000 ppm of the total weight of the slurry.

Biocide used in the CMP polishing slurry compositions is the commercialavailable Kathon type of biocides.

The CMP polishing slurry compositions contain from 0.0001 wt % to 0.05wt % biocide; preferably from 0.0001 wt % to 0.025 wt % and morepreferably from 0.0002 wt % to 0.01 wt %.

EXPERIMENTAL SECTION General Experimental Procedure

The associated methods described herein entail use of the aforementionedcopper or TSV CMP polishing slurry composition for chemical mechanicalplanarization of substrates comprised of copper. In the methods, asubstrate (e.g., a wafer with copper surface) is placed face-down on apolishing pad which is fixedly attached to a rotatable platen of a CMPpolisher. In this manner, the substrate to be polished and planarized isplaced in direct contact with the polishing pad. A wafer carrier systemor polishing head is used to hold the substrate in place and to apply adownward pressure against the backside of the substrate during CMPprocessing while the platen and the substrate are rotated. The polishingslurry composition is applied (usually continuously) on the pad duringcopper CMP processing to effect the removal of material to planarize thesubstrate.

All percentages are weight percentages unless otherwise indicated. Inthe examples presented below, CMP experiments were run using theprocedures and experimental conditions given below. The CMP tool thatwas used in the examples is a Mirra®, manufactured by Applied Materials,3050 Boweres Avenue, Santa Clara, Calif., 95054. An IC-1010 pad or otherpad, supplied by Dow Chemicals or Fujibo, was used on the platen for theblanket copper wafer polishing studies. Other polishing pads, suppliedby Dow Chemicals or Fujibo were also used on the platen for the blanketcopper wafer polishing studies. Pads were broken-in by polishingtwenty-five dummy oxide (deposited by plasma enhanced CVD from a TEOSprecursor, PETEOS) wafers. In order to qualify the tool settings and thepad break-in, two PETEOS monitors were polished with Syton® OX-Kcolloidal silica, supplied by Planarization Platform of Air ProductsChemicals Inc. at baseline conditions. Polishing experiments wereconducted using blanket copper wafer with 15K Angstroms in thickness.These copper blanket wafers were purchased from Silicon ValleyMicroelectronics, 1150 Campbell Ave, Calif., 95126.

Parameters

Å: angstrom(s)—a unit of length

BP: back pressure, in psi units

CMP: chemical mechanical planarization=chemical mechanical polishing

CS: carrier speed

DF: Down force: pressure applied during CMP, units psi

min: minute(s)

ml: milliliter(s)

mV: millivolt(s)

psi: pounds per square inch

PS: platen rotational speed of polishing tool, in rpm (revolution(s) perminute)

SF: polishing slurry composition flow, ml/min

Removal Rates, Defectivity, and Selectivity

Copper RR 2.0 psi Measured copper removal rate at 2.0 psi down pressureof the CMP tool

Copper RR 2.5 psi Measured copper removal rate at 2.0 psi down pressureof the CMP tool and total defects measured by SP2.

Copper RR 3.0 psi Measured copper removal rate at 3.0 psi down pressureof the CMP tool

Ta RR 3.0 psi Measured Ta removal rate at 3.0 psi down pressure of theCMP tool

TaN RR 3.0 psi Measured TaN removal rate at 3.0 psi down pressure of theCMP tool

Ti RR 3.0 psi Measured Ti removal rate at 3.0 psi down pressure of theCMP tool

TiN RR 3.0 psi Measured TiN removal rate at 3.0 psi down pressure of theCMP tool

Si RR 3.0 psi Measured Si removal rate at 3.0 psi down pressure of theCMP tool

Selectivity is calculated of Cu removal rates divided by other filmremoval rates at 3 psi down force.

Total Defect Counts: Collected on the copper blanket wafers polished byusing disclosed herein copper and TSV CMP polishing slurry compositionsat 2.5 psi down force.

Working Example

In the working examples, Polishing pad, IC1010 and other polishing padswere used during CMP, supplied by Dow Chemicals or Fujibo.

The high purity and nano-sized colloidal silica particles were preparedfrom TMOS or TEOS.

Amino acid, glycine, was used as the chelating agent, ethylenediaminewas used as copper film removal rate boosting agent, kathon CG was usedas biocide, 3-amino-1,2,4-triazole was used as corrosion inhibitor,hydrogen peroxide was used as oxidizing agent; and choline bicarbonatewas used as removal rate boosting and defect reducing agent, pH wasbetween 6.5-7.5.

Experiments were conducted using CMP slurry compositions with andwithout choline bicarbonate as the removal rate boosting and defectreducing agent. The polishing performances were compared.

The removal rates results of using choline bicarbonate in the CMP slurrycomposition on copper film at three different down forces were listed inTable 1.

As the results shown in Table 1, with the use of choline bicarbonate asthe chemical additive in the copper CMP slurry composition, the copperfilm removal rates were increased by 11 wt % at 2.0 psi down force, 9 wt% at 2.5 psi down force, and about 10 wt % at 3.0 psi down forcerespectively. In overall, the copper film removal rates were increasedby about 10 wt % at different applied down forces. The averaged about 10wt % increase in copper film removal rate is significant whileconsidering the copper CMP slurry composition being used as referencealready afforded very high copper film removal rates.

TABLE 1 Copper CMP Slurries with/or without Choline Bicarbonate asAdditive on Cu Removal Rates Removal Removal Removal Rate (A/min.) CuSlurry composition Rate (A/min.) Rate (A/min.) at Samples at 2.0 psi at2.5 psi 3.0 psi Reference Cu Slurry 16563 20676 24340 composition (noCholine Bicarbonate) Cu Slurry composition 18386 22540 26741 (withCholine Bicarbonate as additive) Removal Rate Change +11% +9% About +10%

Furthermore, it is important to observe the reduction in total defectswhen choline bicarbonate was used as the chemical additive in the CMPpolishing slurry compositions. The results of the impact of usingcholine bicarbonate as the chemical additive on the total defects werelisted in Table 2.

TABLE 2 Total Defects of Copper CMP Slurries with/or without CholineBicarbonate as Additive Cu Slurry composition Total Samples Defects bySP2 Total Defect Reduction Reference Cu Slurry 429 — composition (noCholine Bicarbonate) Cu Slurry composition 78 about 550% (with CholineBicarbonate as additive)

As the results shown in Table 2, with the use of choline bicarbonate asthe chemical additive in the copper CMP slurry composition, the totaldefects were reduced from 429 for the reference copper CMP slurrycomposition without using choline bicarbonate to 78 for the copper CMPslurry composition using choline bicarbonate as the chemical additive.This represents over 5 times more reduction in total defects. As ageneral matter, it is extremely important to reduce total defects whencopper CMP slurry composition is selected and used for polishing copperfilms in copper CMP or TSV CMP processes.

The impacts of choline bicarbonate as copper film removal rate boostingagent and defect reducing agent were also depicted in FIG. 1 and FIG. 2respectively.

The impacts of the concentrations of chemical additive, cholinebicarbonate, in the copper CMP slurry composition on the copper filmremoval rates at different down forces were also studied. The resultsare listed in Table 3 and FIG. 3 respectively.

TABLE 3 Impacts of Choline Bicarbonate Concentrations in Copper CMPSlurries on Cu Removal Rates. Removal Removal Removal Rate Rate Rate CuSlurry composition (A/min.) at (A/min.) (A/min.) at Samples 2.0 psi at2.5 psi 3.0 psi Reference Cu Slurry 18184 21467 26677 composition (noCholine Bicarbonate) Cu Slurry composition (with 18025 22692 27320 1XCholine Bicarbonate as additive) Cu Slurry composition (with 18823 2362428549 10X Choline Bicarbonate as additive) Cu Slurry composition (with19071 21432 25988 20X Choline Bicarbonate as additive) Removal RateChange Up to +4.9% Up to +10% About +7%

As the results shown in Table 3, in general, copper film removal rateswere increased more at 10× concentrated bicarbonate than theconcentrations at 1× or 20×, respectively.

At 10× concentrated Choline Bicarbonate concentration, the copper filmremoval rate increased % seems higher than that at 20× concentratedCholine Bicarbonate concentration. This might be attributed to the fact10× concentration of choline bicarbonate as additive in the disclosed CuCMP slurry here afforded the optimized removal rate boosting effect thanthe 20× concentration of choline bicarbonate.

The polishing selectivity for copper and other materials such as Ta,TaN, Ti, TiN and Si have also been measured. The selectivity resultswere listed in Table 4, when 3 psi down force was used for polishing.The ratio of the removal rate of copper to the removal rate ofdielectric base is called the “selectivity” for removal of copper inrelation to dielectric during CMP processing of substrates comprised oftitanium, titanium nitride, tantalum, tantalum nitride, and silicon.

TABLE 4 Selective of Cu vs. Other Films Cu:Ta Cu:TaN Cu:Ti Cu:TiN Cu:Si1250 5000 1389 397 253

As the data showed in Table 4, very high selectivity (>1000) wasachieved for Cu:Ta, Cu:TaN, and Cu:Ti, and also reasonable highselectivity was achieved for Cu:TiN and Cu:Si (>250). This highselectivity for polishing copper relative to the other materials ishighly desirable for many applications, such as, TSV applications, thatdemands high copper film removal rates.

While at least one exemplary embodiment has been presented in theforegoing detailed description of the invention, it should beappreciated that a vast number of variations exist. It should also beappreciated that the exemplary embodiment or exemplary embodiments areonly examples, and are not intended to limit the scope, applicability,or configuration of the invention in any way. Rather, the foregoingdetailed description will provide those skilled in the art with aconvenient road map for implementing an exemplary embodiment of theinvention, it being understood that various changes may be made in thefunction and arrangement of elements described in an exemplaryembodiment without departing from the scope of the invention as setforth in the appended claims.

The invention claimed is:
 1. A method of chemical mechanical polishing aremoval material of copper or copper-containing material from a surfaceof a semiconductor substrate comprising steps of: a) providing apolishing pad; b) providing a chemical mechanical polishing slurrycomposition comprising 1) from 0.0 wt % to 25 wt % abrasive; 2) from0.01 wt % to 22 wt % chelating agent; 3) from 0.001 wt % to 0.15 wt %corrosion inhibitor; 4) from 0.0001 wt % to 0.50 wt % choline salt; 5)from 0.0001 wt % to 0.20 wt % organic amine; 6) from 0.01 wt % to 10 wt% oxidizer; 7) from 0.0001 wt % to 0.05 wt % biocide; 8) remaining issubstantially liquid carrier; wherein pH of the polishing slurrycomposition is between 5.0 to 8.0; and the choline salt having a generalmolecular structure shown below:

wherein anion Y⁻ is selected from the group consisting of bicarbonate,p-toluenesulfonate, bitartrate, and combinations thereof; c) contactingthe surface of the semiconductor substrate with the polishing pad andthe chemical mechanical polishing slurry composition; and d) polishingthe surface of the semiconductor substrate; wherein at least a portionof the surface that containing the removal material is in contact withboth the polishing pad and the chemical mechanical polishing slurrycomposition.
 2. The method of claim 1, wherein the abrasive is selectedfrom the group consisting of colloidal silica particles, alumina dopedsilica particles, colloidal aluminum oxide, colloidal and photoactivetitanium dioxide, cerium oxide, colloidal cerium oxide, nano-sizeddiamond particles, nano-sized silicon nitride particles, mono-modal,bi-modal, multi-modal colloidal abrasive particles, zirconium oxide,organic polymer-based soft abrasives, surface-coated or modifiedabrasives, and mixtures thereof; the abrasive having narrow or broadparticle size distributions, with various sizes and different shapesselected from the group consisting of spherical shape, cocoon shape,aggregate shape and combinations thereof; the chelating agent isselected from the group consisting of glycine, amino acids, and aminoacid derivatives; the corrosion inhibitor is selected from the groupconsisting of triazole and its derivatives, benzene triazole and itsderivatives; the organic amine compound agent is selected from the groupconsisting of ethylene diamine, propylene diamine, organic aminecompounds containing multi amino groups in the same molecular framework;the oxidizer is selected from the group consisting of periodic acid,hydrogen peroxide, potassium iodate, potassium permanganate, ammoniumpersulfate, ammonium molybdate, ferric nitrate, nitric acid, potassiumnitrate, and mixtures thereof; and the liquid carrier is water.
 3. Themethod of claim 2, wherein the triazole derivative is selected from thegroup consisting of amino-substituted triazole compounds,bi-amino-substituted triazole compounds, and mixtures thereof.
 4. Themethod of claim 1, wherein the chemical mechanical polishing slurrycomposition further comprising one selected from the group consisting offrom 0.01 wt % to 0.5 wt % pH adjusting agent comprising inorganic ororganic acids; from 0.00 wt % to 1.0 wt % surfactant; and combinationsthereof; wherein: the pH adjusting agent is selected from the groupconsisting of nitric acid, hydrochloric acid, sulfuric acid, phosphoricacid, and mixtures thereof; and the surfactant is nonionic, anionic,cationic or amphoteric surfactant.
 5. The method of claim 1, wherein thechemical mechanical polishing slurry composition comprising nano-sizedcolloidal silica particles prepared from TMOS or TEOS; glycine;ethylenediamine, 3-amino-1,2,4-triazole, hydrogen peroxide; cholinebicarbonate; and the pH is 6.5 to 7.5.
 6. The method of claim 1, whereinthe semiconductor substrate further comprising one selected from thegroup consisting of Ta, TaN, Ti, TiN, Si and combinations thereof; andthe chemical mechanical polishing slurry composition has polishingselectivity of Cu:Ta, Cu:TaN, Cu:Ti Cu:TiN and Cu:Si ranging from about200 to about
 5000. 7. A method of a selective chemical mechanicalpolishing comprising steps of: a) providing a semiconductor substratehaving a surface containing copper metal; b) providing a polishing pad;c) providing a chemical mechanical polishing slurry compositioncomprising 1) from 0.0 wt % to 25 wt % abrasive; 2) from 0.01 wt % to 22wt % chelating agent; 3) from 0.001 wt % to 0.15 wt % corrosioninhibitor; 4) from 0.0001 wt % to 0.50 wt % choline salt; 5) from 0.0001wt % to 0.20 wt % organic amine; 6) from 0.01 wt % to 10 wt % oxidizer;7) from 0.0001 wt % to 0.05 wt % biocide; 8) remaining is substantiallyliquid carrier; wherein pH of the polishing slurry composition isbetween 5.0 to 8.0; and the choline salt having a general molecularstructure shown below:

wherein anion Y⁻ is selected from the group consisting of bicarbonate,p-toluenesulfonate, bitartrate, and combinations thereof; d) contactingthe surface of the semiconductor substrate with the polishing pad andthe chemical mechanical polishing slurry composition; and e) polishingthe surface of the semiconductor substrate to selectively remove coppermetal; wherein at least a portion of the surface containing copper metalis in contact with both the polishing pad and the chemical mechanicalpolishing slurry composition.
 8. The method of claim 7, wherein theabrasive is selected from the group consisting of colloidal silicaparticles, alumina doped silica particles, colloidal aluminum oxide,colloidal and photoactive titanium dioxide, cerium oxide, colloidalcerium oxide, nano-sized diamond particles, nano-sized silicon nitrideparticles, mono-modal, bi-modal, multi-modal colloidal abrasiveparticles, zirconium oxide, organic polymer-based soft abrasives,surface-coated or modified abrasives, and mixtures thereof; the abrasivehaving narrow or broad particle size distributions, with various sizesand different shapes selected from the group consisting of sphericalshape, cocoon shape, aggregate shape and combinations thereof; thechelating agent is selected from the group consisting of glycine, aminoacids, and amino acid derivatives; the corrosion inhibitor is selectedfrom the group consisting of triazole and its derivatives, benzenetriazole and its derivatives; the organic amine compound agent isselected from the group consisting of ethylene diamine, propylenediamine, organic amine compounds containing multi amino groups in thesame molecular framework; the oxidizer is selected from the groupconsisting of periodic acid, hydrogen peroxide, potassium iodate,potassium permanganate, ammonium persulfate, ammonium molybdate, ferricnitrate, nitric acid, potassium nitrate, and mixtures thereof; and theliquid carrier is water.
 9. The method of claim 8, wherein the triazolederivative is selected from the group consisting of amino-substitutedtriazole compounds, bi-amino-substituted triazole compounds, andmixtures thereof.
 10. The method of claim 7, wherein the chemicalmechanical polishing slurry composition further comprising one selectedfrom the group consisting of from 0.01 wt % to 0.5 wt % pH adjustingagent comprising inorganic or organic acids; from 0.00 wt % to 1.0 wt %surfactant; and combinations thereof; wherein: the pH adjusting agent isselected from the group consisting of nitric acid, hydrochloric acid,sulfuric acid, phosphoric acid, and mixtures thereof; and the surfactantis nonionic, anionic, cationic or amphoteric surfactant.
 11. The methodof claim 7, wherein the chemical mechanical polishing slurry compositioncomprising nano-sized colloidal silica particles prepared from TMOS orTEOS; glycine; ethylenediamine, 3-amino-1,2,4-triazole, hydrogenperoxide; and choline bicarbonate; the pH is 6.5 to 7.5; thesemiconductor substrate further comprising one selected from the groupconsisting of Ta, TaN, Ti, TiN, Si and combinations thereof; and thechemical mechanical polishing slurry composition has polishingselectivity of Cu:Ta, Cu:TaN, Cu:Ti Cu:TiN and Cu:Si ranging from about200 to about 5000.